Same way people fall for giveaway scams, it's either out of ignorant (in the sense that, they're not educated/inform on this tricks used by scammers) or they fall because of greed. Humans are greedy naturally, they fully know such offers are unrealistic but their greed will overshadow their reasoning and they'll fall victim. Scammers aren't innovative anymore, they just wait on this two factor to play on their favour, either the victim is ignorant or greedy.

This Chinese scams aren't restricted to only Chinese as any region with restrictions on crypto can be used and most times those behind the mask at the other end aren't really Chinese, they are scammers from all part of the world in disguise and this is sending a wrong impression about Chinese same as it's for other regions that get profiled due to story of scams online.

To protect yourself from all scams, stay updated/informed and most importantly be skeptical about everything except the Bitcoin in your personal wallet because if it's too good to be true then it usually a scam.